This appendix is part of the thesis “Status and trend of brook lamprey (Lampetra planeri) populations in Flanders”. It provides dynamic maps illustrating the presence- and absence of brook lampreys in Belgium, as well as the locations of fish migration barriers and combined sewer overflows (CSO’s). Each map is provided with clickable and toggleable layers, allowing users to view specific components as desired. All watercourse of the VHA (Flemish Hydrographic Atlas) can be viewed when zooming in. The VHA watercourses disappear when changing the base map due to a bug in coding. This can be resolved by reloading the page.



Figure B1 show the general overview of the data and populations. This map shows all electrical sample events with (presence: white) and without (absence: black) observations of brook lamprey from 1989 until 2023. The populations are also included in the map (populations: colours shown in legend). When hovering or clicking the presence- and absence dots, all years in which the location was sampled pop up.

figure B1: General overview of teh data and populations


Figure B2 shows the overview of the fish migration barriers. This maps shows the brook lamprey observations and population delineation with all types of fish migration barriers that occur in the populations. Extra information in Dutch (ID, Name, type etc.) is shown for the barriers when clicking on it.

figure B2: Fish migration barriers


Figure B3 shows an overview of the combined sewer overflows. This map shows shows the brook lamprey observations and population delineation with an overview of the CSO’s.

figure B3: Combined sewer overflows